Niels Bohr

Niels Henrik David Bohr (7 October 1885 – 18 November 1962) was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922. Bohr was at the center of a group of theorists who worked in Copenhagen, sometimes referred to as the Copenhagen School of Physics. He is known for the Bohr model of the atom, his work on the principle of complementarity, and for founding the Niels Bohr Institute. Born in Copenhagen, Denmark, Bohr was a son of Christian Bohr, a professor of physiology at the University of Copenhagen, and Ellen Adler Bohr, who came from a wealthy Jewish family prominent in Danish banking and parliamentary circles. He was educated at the University of Copenhagen, where he earned his Master's degree in 1909 and his doctorate in 1911. After completing his doctoral work, Bohr studied under J.J. Thomson at the Cavendish Laboratory in Cambridge and later worked with Ernest Rutherford at the University of Manchester. It was during his time with Rutherford that Bohr developed his model of atomic structure. In 1913, Bohr published his model of atomic structure, in which he introduced the theory that electrons travel in orbits around the atom's nucleus and that the chemical properties of the element are largely determined by the number of electrons in the outer orbits. Bohr's theory was revolutionary and contributed significantly to the development of quantum mechanics. Despite its success, the Bohr model was later superseded by the more accurate quantum mechanical models, first by the Schrödinger equation and then by the Heisenberg uncertainty principle. Bohr also contributed to the understanding of the atomic nucleus. In 1936, he proposed the liquid drop model to explain the nucleus's structure, which later played a significant role in the development of the theory of nuclear fission. During World War II, Bohr was an active participant in the Manhattan Project, the Allied project to develop atomic bombs. After the war, he became an advocate for the peaceful use of nuclear energy and for international cooperation on nuclear issues. Bohr received numerous awards and honors in his lifetime, including the Nobel Prize in Physics in 1922 for his work on the structure of atoms and their radiation. He was also a foreign member of the Royal Society, the French Academy of Sciences, and the American Philosophical Society. In addition to his scientific work, Bohr was known for his philosophical writings on science and its role in society. His principle of complementarity, which he introduced in 1927, argued that objects could have seemingly mutually exclusive properties, such as being both a particle and a wave, depending on the experimental context. This principle has been influential in the philosophy of science. Bohr died in Copenhagen in 1962. His legacy includes the Niels Bohr Institute, which continues to be a leading center for theoretical physics. The institute is part of the University of Copenhagen and focuses on research in quantum mechanics and related areas.

‎